December, '16] McGREGOR: privet mite in the south . 557 



Character of Attack 



The species is not entirely confined to privet {Ligustmm spp.) 

 hedges but a marked preference seems to be exhibited for this host. 

 A remarkably high percentage of privet hedges are infested and the 

 resulting damage is often very noticeable. Unlike many other pests, 

 the privet gains impetus with the approach of fall and the heaviest 

 infestations usually occur in September and October in the 8outh. 



The feeding takes place on the under surface of the leaves where re- 

 production continues until often the leaves are entirely over-run and 

 swarming \\ith the mites in all stages. No marked discoloration is 

 discernible, as is the case with the common red spider, but a yellow- 

 ing or fading of the infested leaves is usually noticeable. The heavy 

 draining of the vital juices of the leaves through the many feeding 

 punctures causes a marked weakening of the foliage. This, perhaps 

 together with certain toxins introduced by the mouthparts, results 

 finally in the shedding of many leaves until, in severe infestations, the 

 plants become entirely defoliated (see PL 43, fig. 1). 



One season's defoliation rarely results in the death of privet bushes. 

 A second crop of leaves i;s soon developed. Owing, however, to the 

 proximity of the bushes, in the case of hedges, this new foliage gener- 

 ally becomes readily reinfested. Upon the destruction of the secondary 

 foliage the vitality of the bush becomes greatly reduced so that either 

 death or great weakness follows. Often the attack centers acutely 

 upon a single bush with the result that it finally succumbs leaving a 

 gap (see PI. 43, fig. 2) in the hedge which is not easily repaired. 



Food Plants 

 Although by far the commonest host of this pest appears to be privet 

 (Ligustrum amurense and other species), we have records of its occur- 

 rence on Rumex acetoseUa, Oxalis strida, garden mint {Mentha spicata), 

 strawberry, Boston ivy, golden-rod (Solidago sp.), the palm. Phoenix 

 humilis and on orange and lemon. Doubtless this host list is by no 

 means complete, and the diverse nature of the above species indicates 

 that the privet mite is to some extent a general feeder. 



Description 

 Female — Body crimson, with two rather well-defined eye-like spots on cephalo- 

 thorax. Widest at posterior corners of cephalothorax, two-thirds as wide as long. 

 The cephalothorax is narrowed considerably anteriorly, and the abdomen tapers to 

 a rounded tip. The body is armed with a pair of weak spines on the anterior body 

 margin- medially, similar spines immediately before and behind the emarginate 

 eyes, six at the posterior tip of the abdomen, and a few along the body margin, and 

 scattered ones dorsally. The cephalothorax is hardly half as long as broad, with 

 the anterior margin convex; the palpi greatly resembles the Tetranychus type, the 

 penultimate joint bears a strong claw, and the terminal joint (thumb) bears a "finger." 

 The legs are relatively stout, crenulated; forelegs in length thi'ee-quarters the width 

 of cephalothorax; four anterior tarsi blood-red in life; all legs bearing several lateral 

 hairs, and a terminal bristle in length equalhng the three distal segments; the tro- 



